The greatest flesh-eaters see badly, but they scrape the bottom with a divining touch and scent their prey at astonishing distances.
Only the Mediterranean fishes, especially those of the Gulf of Naples, were living in the tanks of this Aquarium.

Some were lacking,--the dolphin, of nervous movement, and the tunny, so impetuous in its career.

The captain smiled upon thinking of the mischievous pranks of these ungovernable guests whose presence had been declined.
The voracious shark (_cabeza de olla_), the persecuting wolf of the Mediterranean herds, was not here either.

In his place were swimming other animals of the same species, whitish and long, with great fins, with eyes always open for lack of movable eyelids, and a mouth split like a half-moon, under the head at the beginning of the stomach.
Ferragut sought on the bottom of the tanks the fishes of the deep,--flattened animals that pass the greater part of their time sunk in the sand under a coverlet of algae.

The dark _uranoscopo_, with its eyes almost united on the peak of its enormous head and its body in the form of a club, leaves visible only a long thread coming from its lower jaw, waving it in all directions in order to attract its prey.
Believing it a worm, the victims usually chase the moving bait until pounced upon by the teeth of the hunter who then springs from his bed, floats around for a few moments, and falls heavily to the bottom, opening a new pit with his pectoral, shovel-shaped swimming bladders.
The toad fish, the most hideous animal of the Mediterranean, goes hunting in the same way.